亚当·斯密和大卫·李嘉图是两位重要的经济学理论创立者。斯密证明了私人利益是推动市场效率及公共事业前进的动力,且这种推动力是合理的、并非不道德的。李嘉图在其理论基础上继承发展并解释了资源税的概念,但他认为空气、水等自然资源理所应当是没有价值的,应该被免费使用,这种观念被认可并一直持续了200年。在刚刚过去的20年里,我们重新审视整个经济环境,私人利益是合理的市场效率推动力的说法在华尔街已经失去了公信力,人们更倾向于认为它代表着企业家露骨的贪婪。因此,直到干净的水资源已不再丰富,水才终于拥有了市场价值——我们 Adam Smith and David Ricardo are the two founding fathers of economic theory. Smith proved that private interests are the driving force behind the market efficiency and the progress of public utilities. And this impetus is reasonable and not immoral. Ricardo, on the basis of his theory, inherited and developed the concept of resource tax, but he believes that the natural resources such as air and water should be worthless and should be used for free. This concept has been approved and has been going on for 200 years. In the last two decades we have re-examined the entire economic environment and the claim that private interest is a reasonable driver of market efficiency has lost credibility on Wall Street and people are more inclined to think it represents the explicit greed of entrepreneurs. Therefore, water does not finally have market value until clean water is no longer abundant - we